PCI(3) | Library Functions Manual | PCI(3)

# NAME

pci — library interface for PCI bus access

# LIBRARY

PCI Bus Access Library (libpci, -lpci)

# SYNOPSIS

#include <pci.h>

int
pcibus_conf_read(int pcifd, u_int bus, u_int dev, u_int func, u_int reg, pcireg_t *valp);

int
pcibus_conf_write(int pcifd, u_int bus, u_int dev, u_int func, u_int reg, pcireg_t val);

int
pcidev_conf_read(int devfd, u_int reg, pcireg_t *valp);

int
pcidev_conf_write(int devfd, u_int reg, pcireg_t val);

char *
pci_findvendor(pcireg_t id_reg);

void
pci_devinfo(pcireg_t id_reg, pcireg_t class_reg, int showclass, char *devinfo, size_t len);

void
pci_conf_print(int pcifd, u_int bus, u_int dev, u_int func);

int
pci_drvname(int pcifd, u_int dev, u_int func, char *drvname, size_t len);

# DESCRIPTION

The pci library provides support for accessing the PCI bus by user programs.

These functions are available in the libpci library. Programs should be linked with -lpci.

# CONFIGURATION SPACE FUNCTIONS

The following functions are used to access PCI configuration space:

pcibus_conf_read()
  Access the PCI configuration register reg on the device located at bus, dev, func, and place the result in *valp. pcifd must be an open file descriptor to a PCI bus within the target PCI domain.
pcibus_conf_write()
  Write the value specified by val into the PCI configuration register reg on the device located at bus, dev, func. pcifd must be an open file descriptor to a PCI bus within the target PCI domain.
pcidev_conf_read()
  Access the PCI configuration register reg on the device associated with the open file descriptor devfd and place the result in *valp.
pcidev_conf_write()
  Write the value specified by val into the PCI configuration register reg on the device associated with the open file descriptor devfd.

# MISCELLANEOUS FUNCTIONS

The following miscellaneous functions are available:

pci_findvendor()
  Return an ASCII description of the PCI vendor in the PCI ID register id_reg.
pci_devinfo()
  Return an ASCII description of the PCI vendor, PCI product, and PCI class specified by the PCI ID register id_reg and PCI class ID register class_reg. The description is placed into the buffer pointed to by devinfo; the size of that buffer is specified in len. If showclass is not 0, the class, subclass and interface are added into the buffer.
pci_conf_print()
  Print the PCI configuration information for the device located at bus, dev, func. pcifd must be an open file descriptor to a PCI bus within the target PCI domain.
pci_drvname()
  For the PCI bus opened on pcifd, return the driver name for dev and func into drvname using len as the buffer length.

# RETURN VALUES

The pcibus_conf_read(), pcibus_conf_write(), pcidev_conf_read(), pcidev_conf_write(), pci_devinfo(), and pci_drvname() functions return 0 on success and -1 on failure.

The pci_findvendor() function returns NULL if the PCI vendor description cannot be found.

# SEE ALSO

pci(4)

# HISTORY

The pcibus_conf_read(), pcibus_conf_write(), pcidev_conf_read(), pcidev_conf_write(), pci_findvendor(), pci_devinfo(), and pci_conf_print() functions first appeared in NetBSD 1.6. The pci_drvname() function first appeared in NetBSD 7.0.

December 16, 2014 | NetBSD 7.2